What determiner if the recharge start counting at the end of duration of at cast.
IE mehier’s will CD start after duration, blood of dgree start at cast.
What about skill such as fighting spirit or devotion (like giants blood or dryad)?
Cooldown generally starts as soon as a skill activates. This applies to skills, devotions, items, chance on attack procs, chance when hit procs, etc. Items can be tricky though because some will actually pause their cooldowns if you unequip them.
Skills like Menhir’s Will are more the exception rather than the rule.